From YoJoe.com "Toy Fair 2005 revealed a huge surprise for the G.I. Joe brand. First it was announced that G.I. Joe in its previous incarnations would effectively cease to exist. The 3 3/4" line is on "hiatus" until further notice while the 12" line has been cancelled. However, this is not the end of G.I. Joe as a brand.
Hasbro unveiled a new line of figures at 8" in scale that will be called Sigma Six; using familiar character names from the 3 3/4" line - Storm Shadow, Duke, Spirit, Heavy Duty and Snake-eyes thus far.